Colored golf ball

ABSTRACT

In a colored golf ball having a core, a cover of at least one layer encasing the core and a coat of paint applied to a surface of an outermost layer of the cover, the outermost cover layer is formed of a resin composition which includes (a) a thermoplastic resin, (b) a color pigment or dye, (c) titanium oxide, and (d) a lubricant. The resin composition has a total light transmittance of at least 1.0 but not more than 40, and a diffuse transmittance of at least 1.0 but not more than 40. The paint coat contains a polarizing pigment. The ball has an excellent visibility and stylishness and, in spite of being pastel-colored, is endowed with an appearance that is lustrous and elegant.

CROSS-REFERENCE TO RELATED APPLICATION

This non-provisional application claims priority under 35 U.S.C. §119(a)on Patent Application No. 2010-176316 filed in Japan on Aug. 5, 2010,the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a colored golf ball.

2. Prior Art

Not all golf balls lately are white; a variety of colored balls haveappeared on the market in response to golfer's preferences. Inparticular, highly stylish colored golf balls and colored golf ballshaving an elegant feel are being developed to suit the tastes of womengolfers.

Colored balls with an elegant appearance that are currently sold on themarket include balls having a fluorescent outermost layer coated on thesurface with paint containing a polarizing pigment. Pastel colored golfballs have also been around for some time. However, pastel balls containa large amount of titanium oxide in the material forming the outermostlayer, and thus often end up having a non-transparent (matte) shade ofcolor. Even when a metal oxide-containing paint is applied to theoutermost layer of such a ball, this does not produce a shade of colorhaving a lustrous, transparent feel, and so an elegant appearance is notachieved.

Examples of prior art relating to colored golf balls include JP-A2000-254250, JP-A 2004-033594, JP-A 2007-144097 and JP-A 2009-45347 (andthe corresponding U.S. Pat. Application 20090054176). However, none ofthese provide pastel colored golf balls having a lustrous and elegantfeel.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a coloredgolf ball which has excellent visibility and stylishness and moreoverwhich, although having a pastel tone, is endowed with a lustrous andelegant appearance.

The inventors have discovered that, by forming the outermost layer ofthe cover of a golf ball from a resin composition having a specifictotal light transmittance and a specific diffuse transmittance, andadditionally coating thereon a polarizing pigment-containing paint so asto form a paint coat, it is possible to achieve a color tone which,although in a pastel shade, is lustrous and has a sense of transparency,thus giving a colored golf ball endowed with outstanding visibility andstylishness and an elegant feel.

Accordingly, the present invention provides a colored golf ball composedof a core, a cover of at least one layer encasing the core, and a coatof paint applied to a surface of an outermost layer of the cover. Theoutermost cover layer is formed of a resin composition which includes(a) a thermoplastic resin, (b) a color pigment or dye, (c) titaniumoxide, and (d) a lubricant. The resin composition has a total lighttransmittance of at least 1.0 but not more than 40, and a diffusetransmittance of at least 1.0 but not more than 40. The paint coatcontains a polarizing pigment.

The color pigment or dye (b) is preferably selected from the groupconsisting of red pigments, blue pigments, yellow pigments, greenpigments, purple pigments and black pigments.

The resin composition is preferably formulated as follows: (a) from 90to 99 wt % of a thermoplastic resin, (b) from 0.003 to 2 wt % of a colorpigment or dye, (c) from 0.01 to 2.5 wt % of titanium oxide, and (d)from 0.1 to 5.5 wt % of a lubricant.

It is preferable for the ball to have a surface with a color tone which,expressed numerically in the L*a*b* color space according to JIS Z8729,is: L*=50 to 95, a*=−20 to 30, and b*=−45 to 45.

Preferably, the paint coat includes 100 parts by weight of a base resin,from 0.05 to 1 part by weight of a fluorescent whitener and from 0.1 to3 parts by weight of a polarizing pigment per 100 parts by weight of abase resin, and the fluorescent whitener and polarizing pigment have aweight ratio therebetween of from 0.05 to 5.0.

The golf ball of the invention has a color tone with a luster and senseof transparency not previously achieved in pastel golf balls, and isthus endowed with outstanding visibility and stylishness and an elegantfeel.

BRIEF DESCRIPTION OF THE DIAGRAM

FIG. 1 is a schematic cross-sectional view of a golf ball according toone embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The objects, features and advantages of the invention will become moreapparent from the following detailed description, taken in conjunctionwith the foregoing diagram.

In the colored golf ball of the invention, the outermost layer of thecover is formed of a resin composition having a total lighttransmittance and a diffuse transmittance within specific ranges, andhas thereon a paint coat formed by the application of a polarizingpigment-containing paint.

The construction of the inventive golf ball, so long as it has a coreand a cover of at least one layer, the cover having an outermost layerwith a paint coat on the surface thereof, may be suitably selectedwithin a range that does not depart from the objects of the invention.For example, in the case of three-piece solid golf ball having atwo-layer cover composed of an inner cover layer (intermediate layer)and an outer cover layer (outermost layer), as shown in FIG. 1, the golfball G may be one having a three-piece construction composed of at leasta core 1, an inner cover layer (intermediate layer) 2 encasing the core1, and an outer cover layer 3 encasing the inner cover layer 2, andhaving also thereon a coat of paint 4. In cases where the ball has acover with a multilayer construction of two or more layers, the coverlayers are sometimes referred to collectively herein as the “cover.”That is, in the case of the three-piece solid golf ball shown in FIG. 1,the intermediate layer 2 and the outer cover layer 3 are sometimesreferred to collectively as the “cover.” In such a case, a plurality ofdimples D are generally formed on the surface of the outer cover layer3, which is the outermost layer of the ball. Although FIG. 1 shows anarrangement in which a core 1, an intermediate layer 2 and an outercover layer 3 are formed as a three-layer construction, as noted above,this arrangement may be suitably varied within a range that does notdepart from the objects of the invention. For example, if necessary, usemay be made of an arrangement wherein the cover is composed of only onelayer—the outer cover layer 3, or an arrangement wherein the cover hasthree or more layers, including at least two intermediate layers 2. Itis also possible to form the core 1 as a plurality of layers. Thecolored golf ball is described in detail below while referring to FIG.1.

The core 1 may be obtained by vulcanizing a rubber composition preparedby blending a known rubber material such as cis-1,4-polybutadiene as thebase together with a co-crosslinking agent (e.g., an unsaturatedcarboxylic acid, or a metal salt thereof), an inorganic filler (e.g.,zinc oxide, barium sulfate) and an organic peroxide (e.g., dicumylperoxide, 1,1-bis(t-butylperoxy)cyclohexane). In the present invention,no particular limitation is imposed on the core diameter. Nor is anyparticular limitation imposed on the color of the core.

The intermediate layer 2 may be formed primarily of a resin materialwhich is any of various thermoplastic resins or thermoplasticelastomers, such as known ionomeric resins and polyurethanes. Thisintermediate layer 2, as mentioned above, may be formed as two or morelayers using similar or dissimilar materials, depending on the ballspecifications and the like. The method of molding the intermediatelayer 2 is not subject to any particular limitation; a known method suchas injection molding may be suitably selected for this purpose. Thethickness of the intermediate layer 2 is not subject to any particularlimitation, provided it is suitable for the ball specifications and thelike. In cases where the cover encasing the core 1 is a single layer, anintermediate layer 2 is not formed, the cover being formed over the core1 from the subsequently described outermost layer-forming resincomposition.

The outer cover layer 3 is formed of a resin composition which includesas the essential ingredients: (a) a thermoplastic resin, (b) a colorpigment or dye, (c) titanium oxide, and (d) a lubricant. The respectiveingredients of this outer cover layer (outermost layer)-forming materialare described in detail below.

(a) Thermoplastic Resin

The thermoplastic resin serving as component (a) is the primarycomponent in the outer cover layer-forming material. Various knownthermoplastic resins may be used without particular limitation.Specifically, preferred use may be made of olefinic thermoplastic resinsand thermoplastic polyurethanes. Of these, the use of nonionic resinssuch as olefin-unsaturated carboxylic acid copolymers andolefin-unsaturated carboxylic acid-carboxylic acid ester copolymers, orof ionic resins or thermoplastic polyurethanes is especially preferred.These may be used singly or as combinations of two or more thereof.

When two or more of the above resins are used together, although notsubject to any particular limitation, it is preferable to use an ionicresin and/or a nonionic resin in combination with a thermoplasticpolyurethane. In such a case, the relative proportions by weight of theionic resin and/or nonionic resin (when used together, the combinedamount of both) and the thermoplastic polyurethane, while not subject toany particular limitation, is preferably from 100:0.1 to 100:10, andmore preferably from 100:0.5 to 100:5. By setting the relativeproportions of both in the above range, a cover having a suitable lighttransmittance can be formed, in addition to which coloration havingdepth is possible, enabling the elegant feel of the golf ball as a wholeto be increased.

Use can be made of known ionic resins and nonionic resins withoutparticular limitation. Illustrative examples of ionic resins that may beused include those available under the trade names HIMILAN 1601, HIMILAN1605, HIMILAN 1557 and HIMILAN 1855 (all products of DuPont-MitsuiPolychemicals), and those available under the trade names IOTEK 8030 andIOTEL 7010 (ExxonMobil). Illustrative examples of nonionic resins thatmay be used include that available under the trade name NUCREL N035C(DuPont-Mitsui Polychemicals).

Use may likewise be made of known thermoplastic polyurethanes withoutparticular limitation. Illustrative examples include those availableunder the trade names PANDEX T8295 and PANDEX T8260 (DIC Bayer Polymer).

The proportion in which component (a) is included may be set to from 90to 99 wt %, and preferably from 93 to 99 wt %. Outside of the aboverange, the ball may have a poor scuff resistance and durability.

(b) Color Pigment or Dye

The color pigment or dye serving as component (b) is included for thepurpose of adjusting the perceived color of the ball. In the practice ofthe invention, a known pigment or dye may be used. From the standpointof discoloration resistance, the use of a pigment is preferred.Exemplary pigments include red pigments, blue pigments, yellow pigments,green pigments, violet pigments and black pigments. More specifically,examples of red pigment include quinacridone pigments, examples of bluepigments include phthalocyanine pigments, examples of yellow pigmentsinclude complex oxide pigments, examples of violet pigments includeultramarine violet, cobalt violet, manganese violet, dioxane violet andquinacridone violet; and examples of black pigments include carbonblack. By including these, it is possible to express pastel colorshaving depth. These pigments may be used singly or as combinations oftwo or more thereof; the combinations or included amounts of thesepigments may be suitably selected according to the ball specificationsand the like. Commercial products may be used as the above pigments.Specific examples of such commercial products include those availableunder the trade names CHROMOFINE (Dainichi Seika Color & Chemicals Mfg.Co., Ltd.), TIPAQUE YELLOW (Ishihara Sangyo Kaisha, Ltd.) and TOKABLACK(Tokai Carbon Co., Ltd.). The proportion in which component (b) isincluded may be set to from 0.003 to 2 wt %, and more preferably from0.005 to 1.5 wt %. When the amount of component (b) added is too low,coloration may be poor. When too much is added, coloration may beexcessive, resulting in the loss of a pastel feel.

(c) Titanium Oxide

The titanium oxide serving as component (c) is included for the purposeof enhancing the ability to hide the outermost layer-forming resincomposition. In the practice of this invention, by adjusting the amountin which the titanium oxide is included, the extent to which theunderlying layer shows through can be changed, in addition to which thedegree of coloration can be varied. In this invention, a known titaniumoxide may be used. For example, preferred use may be made of productscommercially available under the trade name TIPAQUE (Ishihara SangyoKaisha). This titanium oxide may also be used as a white pigment,enabling depth to be imparted to the perceived color of the ball. Theproportion in which component (c) is included may be set to from 0.01 to2.5 wt %, and more preferably from 0.05 to 2 wt %. If the amount ofcomponent (c) added is too low, the hiding power may be inadequate,allowing the underlying color to affect ball coloration. On the otherhand, the addition of too much component (c) may increase the sense ofopacity, resulting in a loss of the elegant feel.

(d) Lubricant

The lubricant serving as component (d) is an ingredient which functionsas, for example, a processing aid, a slip enhancer and a dispersant.Exemplary lubricants include organic acids such as fatty acids, fattyacid metal salts and fatty amides, as well as acrylic polymers andsilicones. The proportion in which component (d) is included may be setto from 0.1 to 5.5 wt %, and preferably from 1 to 3 wt %. If the amountof component (d) is too small, the composition may not have good flowproperties, which may make molding impossible to carry out. On the otherhand, if too much component (d) is added, the lubricant may bleed out,possibly marring the appearance of the ball surface or resulting in pooradhesion with the paint coat 4 or the underlying layer (the intermediatelayer 2 or the core 1).

(e) Additives

In addition to above components (a) to (d), it is possible to includealso various types of additives as component (e). Additives for variousresin applications may be used, such as antioxidants, ultravioletabsorbers, flow enhancers and thickeners. The amount in which theseadditives are added is not subject to any particular limitation and maybe suitably selected within a range that does not adversely affect themoldability and other properties of the resin composition. Typically,the amount of use per 100 wt % of above component (a) may be set to from0.05 to 5 wt %, and preferably from 0.1 to 4 wt %.

The outer cover layer 3 formed using the resin composition formulatedfrom the above components may be set to a thickness of from 0.3 to 2.1mm, and preferably from 0.5 to 1.7 mm. If the thickness of the outercover layer 3 is too small, the underlying material may show through,detracting from the ball coloration. On the other hand, if the thicknessis too large, uniform injection molding may be difficult to carry out,resulting in a loss in the sense of ball quality.

The outer cover layer-forming material has a haze value of at least 80but not more than 100, and preferably at least 90 but not more than 100.If the haze value is too low, the balance between the sense oftransparency and the pastel feel may worsen, possibly detracting fromthe sense of elegance of the ball's appearance. The total lighttransmittance is at least 1.0 but not more than 40, and preferably atleast 1.0 but not more than 30. If the total light transmittance is toolarge, the transparency may be excessive, as a result of whichpastel-toned colors may not be achieved. Also, the diffusiontransmittance is at least 1.0 but not more than 40, and preferably atleast 1.0 but not more than 30. If the diffusion transmittance is toolarge, the transparency may be excessive, as a result of whichpastel-toned colors may not be achieved.

As used herein, “total light transmittance” and “diffuse transmittance”refer respectively to the degree of light transmission and the degree oflight diffusion when light from a light source is applied through aplastic (outer cover layer material) test specimen, these being valuesobtained in accordance with JIS K7105 (1981).

“Haze” refers to a value computed by the following formula from theabove total light transmittance and diffuse transmittance. Referenceshould be made to JIS K7136 (2000) for further details.

Haze(%)=(diffusion transmittance T _(d))/(total light transmittance T_(t))×100

In the above description, a larger total light transmittance valueindicates that light passes through more easily and the degree oftransparency is higher; conversely, a smaller value indicates that lightpasses through with greater difficulty and the degree of transparency islower. In the case of both the diffuse transmittance and the Haze value,smaller values indicate a greater degree of clouding; conversely, largervalues indicate less light diffusion and a high degree of transparency.

Preparation of the above-described material may be carried out using aknown mixing apparatus, such as a single-screw extruder or a twin-screwextruder. In this invention, the use of a twin-screw extruder ispreferred. Alternatively, these extruders may be used in a tandemarrangement, such as single-screw extruder/twin-screw extruder ortwin-screw extruder/twin-screw extruder. These extruders need not be ofa special design; the use of existing extruders will suffice. The methodof molding the cover using the above material is not subject to anyparticular limitation. For example, use may be made of an injectionmolding process or a compression molding process. In cases where aninjection molding process is used, the process may one in which aprefabricated core is placed at a predetermined position in an injectionmold, following which the above material is introduced into the mold.Alternatively, in cases where a compression molding process is used, theprocess may be one in which a pair of half-cups is produced of the abovematerial, the cups are placed over a core, and heat and pressure areapplied within a mold. When molding is carried out under applied heatand pressure, the molding conditions employed may be a temperature offrom 120 to 170° C. and a molding time of from 1 to 5 minutes.

As shown in FIG. 1, the surface of the outer cover layer 3 is coveredwith a coat of paint 4. The thickness of this paint coat 4, although notsubject to any particular limitation, is preferably at least 5 and morepreferably at least 10 μm, but preferably not more than 20 μm, and morepreferably not more than 16 μm. If the paint coat 4 is too thin, thedurability of the coat may be inadequate. On the other hand, if thepaint coat 4 is too thick, this may lower the rebound of the ball andmay lead to peeling of the paint.

This paint coat 4 is formed by applying a paint composed of a base resinsuch as polyurethane, to which a polarizing pigment and various solventsand additives have been suitably added. The paint coat has a sense oftransparency due to synergistic effects with the perceived color of theouter cover layer 3, thereby enabling a pastel-toned color that islustrous and has an elegant feel to be obtained.

The base resin of the paint is not subject to any particular limitation.For example, use may be made of a known urethane resin. However, in thisinvention, the use of a two-component curing urethane paint composed ofa polyol component having hydroxyl groups and a polyisocyanate componenthaving isocyanate groups is preferred. Examples of polyols that may beprimarily used include urethanes, polyesters and acrylic resins,although other resins, such as epoxy resins, may be employed ifnecessary. Examples of polyisocyanates that may be used include tolylenediisocyanate, diphenylmethane-4,4′-diisocyanate, hexamethylenediisocyanate, isophorone diisocyanate, naphthalene diisocyanate,1,4-phenylene diisocyanate, xylylene diisocyanate and hydrogenatedxylylene diisocyanate, either singly or in modified forms ascombinations thereof. The polyisocyanate component may generally takethe form of an adduct, a biuret or an isocyanurate.

The polarizing pigment is included so as to enhance the elegant feel andsense of quality of the golf ball. For example, metal powder pigments,glass flakes, mica and pearlescent pigments may be included. In thepresent invention, the use of a pearlescent pigment is especiallypreferred. Any of the following may be used as the pearlescent pigment:metal oxide-coated mica, basic lead carbonate, bismuth oxychloride, andnatural pearl essence. Of these, the selection of a metal oxide-coatedmica is preferred because such pigments are nontoxic and have the bestchemical stability. In such a metal oxide-coated mica, titanium dioxideor iron oxide is typically used as the metal oxide which coats the mica;by varying the coverage (thickness of the coating layer), variousperceived colors and interference effects can be achieved. The particlesize of the polarizing pigment is not subject to any particularlimitation. However, because the pigment has a greater tendency tosettle at a larger particle size, it is desirable to select a pigmenthaving a suitable particle size. A commercial product may be used as theabove polarizing pigment. Examples of such products are those availableunder the trade name XIRALLIC (Merck Japan).

The amount of polarizing pigment included per 100 parts by weight of thebase resin may be set in a range of from 0.1 to 3 parts by weight, andpreferably from 0.2 to 2 parts by weight. If the amount of polarizingpigment is too low, a suitable luminosity and brightness will be lost,as a result of which an elegant feel may not be achieved. On the otherhand, including too much polarizing pigment may make the paintingoperation more difficult or may become a major cause in peeling of thepaint coat.

In addition, to increase the luminosity of the paint, it is preferableto include a fluorescent whitener. The amount of fluorescent whitenerincluded per 100 parts by weight of the base resin may be set to from0.05 to 1 part by weight, and is more preferably used in such a way thatthe relative proportions of fluorescent whitener to polarizing pigment(fluorescent whitener/polarizing pigment), expressed as a weight ratio,are from 0.05 to 5.0.

Any known method used in the art may be employed as the method forapplying the paint. For example, the entire ball may be spray-paintedwhile perched on the tips of needles on a needle bed. Alternatively,prior to painting, to improve adhesion between the object to be painted(a sphere covered by the outer cover layer 3) and the paint coat 4,although not subject to any particular limitation, surface modificationby plasma treatment or corona discharge treatment may be carried out, ora primer or the like may be applied.

The color of the outer cover layer-forming resin composition and thecolor of the colored golf ball after the coat of paint 4 has been formedon the surface of the outer cover layer 3 (i.e., after painting) may besuitably set according to the ball specifications and the like, and arenot subject to any particular limitation. However, in this invention, itis preferable to set the color as follows in the L*a*b* color spaceaccording to JIS 28729.

First, with regard to the L*, a* and b* values of the outer coverlayer-forming composition, the L* value is from 65 to 95, and preferablyfrom 70 to 90; the a* value is from −15 to 15, and preferably from −12to 12; and the b* value is from −35 to 30, preferably from −25 to 30,and more preferably from −18 to 28. When the color of this compositionfalls outside of the above ranges, the perceived color that is desiredmay not be attainable. For example, in cases where the L* value issmaller than the above range, the darkness increases, as a result ofwhich a pastel feel may be lost.

Next, with regard to the L*, a* and b* values of the colored golf ballafter it has been painted, the L* value is from 50 to 95, and preferablyfrom 60 to 90; the a* value is from −20 to 30, and preferably from −15to 15; and the b* value is from −45 to 45, and preferably from −35 to30. Moreover, the saturation C, expressed as (a*²+b*²)^(0.5), may be setto from 5 to 50, and preferably from 10 to 40. When the ball color fallsoutside of the above range, the perceived color that is desired may notbe attainable. For example, in cases where the L* value is smaller thanthe above range, the darkness increases, as a result of which a sense ofelegance may be lost.

Moreover, although not subject to any particular limitation, it isdesirable for the L* value of the colored golf ball to be smaller thanthe L* value of the intermediate layer 2. When the L* value of theintermediate layer 2 is smaller than the L* value of the ball, the colorof the intermediate layer 2 becomes relatively dark, which may influencethe overlying outermost layer (outer cover layer 3) lying thereabove. Inaddition, although not subject to any particular limitation, it isrecommended that the L* value difference between the intermediate layer2 and the outer cover layer 3 be set to preferably from 1 to 30, andmore preferably from 1 to 25. If this difference is too small, a senseof transparency may be lost. On the other hand, if it is too large, apastel feel may be lost.

The golf ball of the invention, which can be manufactured so as toconform with the Rules of Golf for competitive play, may be produced toa ball diameter which is not less than 42.67 mm and to a weight which isnot more than 45.93 g.

EXAMPLES

The following Examples are provided to illustrate the invention, and arenot intended to limit the scope thereof.

Examples 1 to 4 Comparative Examples 1 to 4

A rubber composition having a common formulation for each example of theinvention and each comparative example was prepared, masticated in akneader or roll mill, then fashioned into a core under specificvulcanization conditions. Next, in each example, the intermediatelayer-forming material shown in Table 1 and the outer coverlayer-forming material shown in Table 2 were successivelyinjection-molded over the resulting core to form a ball. A two-componentcuring urethane paint of the following formulation was thenspray-painted onto the surface of the ball and dried, thereby producingcolored golf balls in the respective examples of the invention andcomparative examples. The numbers in the resin mixing materialformulations shown in Tables 1 and 2 indicate parts by weight.

Rubber Formulation

Polybutadiene rubber 100 parts by weight Zinc acrylate 29 parts byweight Peroxide 1.2 parts by weight Antioxidant 0.1 part by weight Zincoxide 26.7 parts by weight Zinc salt of pentachlorothiophenol 0.2 partby weight Red pigment 0.08 part by weight

Vulcanization of the above rubber was carried out at 155° C. for 15minutes. The peroxide was a mixture of 1,1-di(t-butylperoxy)cyclohexaneand silica that is available under the trade name PERHEXA C-40 (NOFCorporation). The antioxidant was NOCRAC NS-6 (Ouchi Shinko ChemicalIndustry Co., Ltd.).

TABLE 1 Intermediate layer-forming material a b Ionomers SURLYN 6320(trade name) 60 60 NUCREL 035C (trade name) 40 40 Fatty acid Magnesiumstearate 69 69 Cation Magnesium oxide 0.8 0.8 Colorants Titanium oxide4.1 Magnesium stearate 1.0 Yellow pigment 0.02

The materials mentioned in the table are described below.

-   SURLYN 6320: A magnesium-neutralized ethylene-methacrylic    acid-acrylic acid ester copolymer available from E.I. DuPont de    Nemours & Co.-   NUCREL 035C: An ethylene-methacrylic acid-acrylic acid ester    copolymer available from DuPont-Mitsui Polychemicals Co., Ltd.-   Magnesium stearate: Available from Dainichi Kagaku under the trade    name M-5GN.-   Magnesium oxide: Magnesium oxide available from Kyowa Chemical    Industry.-   Titanium oxide: Available from Ishihara Sangyo Kaisha under the    trade name TIPAQUE R550.

Paint Formulation

Base resin 98.5 wt %  Polarizing pigment 1.0 wt % Fluorescent whitener0.5 wt %

Details of the above materials are provided below.

-   Base resin: two-component curing urethane paint-   Polarizing pigment: Available from Merck under the trade name    IRIODIN.

The appearance-related properties of the covers and golf balls obtainedas described above in the respective examples of the invention andcomparative examples were rated according to the following criteria. Theresults are shown in Table 2.

Total Light Transmittance and Diffusion Transmittance

Measurement was carried out under the following conditions using a lighttransmittance measuring instrument (Turbidimeter NDH5000W, manufacturedby Nippon Denshoku Industries Co., Ltd.). The total light transmittanceand diffuse transmittance were determined in accordance with JIS K7105,and the Haze value was determined in accordance with JIS K7136.

-   -   Measurement conditions: Light source, D65; measurement method, 3    -   Number of measurements: n=3 for each sample

The total light transmittance and the diffuse transmittance wereobtained by directing the light source at a test specimen, measuring howmuch of the light passed through and how much diffused through the testspecimen, and converting the results to numerical values. Larger valuesindicate a higher degree of transparency, and smaller values indicate alower degree of transparency. Normally, when these measurements arecarried out on a resin composition containing titanium oxide, the valuesobtained are substantially 0.

Ball Color

The color tone of the ball after topcoating was measured using a colordifference meter (model SC-P, manufactured by Suga Test Instruments Co.,Ltd.) and with a C light source having a 2° field, in accordance withJIS Z 8722-1994, Condition c (Measurement of Reflection (diffusedillumination, 8° viewing angle (d/8: excluding specularly reflectedcomponent)), and was converted to a numerical value based on JISZ8729-1994 (L*A*B* color system). A measurement area diameter of 30 mmwas used.

Weatherability

Each type of ball (n=3) was exposed to sunlight together with an indexball. AE was measured at fixed intervals with a Lab color differencemeter. When the ΔE of the index ball became 15 or more, exposure tosunlight was stopped, and the ΔE for each ball at that time wasmeasured. The weatherability was rated according to the following ΔEcriteria.

-   -   Excellent: less than 5    -   Good: 5 or more, but less than 13    -   Fair: 13 or more

Elegant Feel

Sensory evaluations based on the following criteria were carried out byten skilled golfers.

-   -   Excellent: Eight or more of the ten golfers thought the ball had        an elegant feel.    -   Good: Five to seven of the ten golfers thought the ball had an        elegant feel.    -   Fair: Three or four of the ten golfers thought the ball had an        elegant feel.    -   NG: Two or less of the ten golfers thought the ball had an        elegant feel.

Pastel Feel

Sensory evaluations based on the following criteria were carried out byten skilled golfers.

-   -   Excellent: Eight or more of the ten golfers thought the ball had        a “pastel feel” (left an impression of a soft, intermediate        color).    -   Good: Five to seven of the ten golfers thought the ball had a        “pastel feel” (left an impression of a soft, intermediate        color).    -   Fair: Three or four of the ten golfers thought the ball had a        “pastel feel” (left an impression of a soft, intermediate        color).    -   NG: Two or less of the ten golfers thought the ball had a        “pastel feel” (left an impression of a soft, intermediate        color).

Transparent Feel

Sensory evaluations based on the following criteria were carried out byten skilled golfers.

-   -   Excellent: Eight or more of the ten golfers thought the ball had        a “transparent feel” (left an impression of color depth and        solidity).    -   Good: Five to seven of the ten golfers thought the ball had a        “transparent feel” (left an impression of color depth and        solidity).    -   Fair: Three or four of the ten golfers thought the ball had a        “transparent feel” (left an impression of color depth and        solidity).    -   NG: Two or less of the ten golfers thought the ball had a        “transparent feel” (left an impression of color depth and        solidity).

TABLE 2 Example Comparative Example 1 2 3 4 1 2 3 4 Outermost Coloryellow yellow purple purple yellow pink blue yellow layer Pigment/dyetitanium quinacridone red cyclic anthra- ultra- titanium formulationyellow (0.8)  dye quinone marine yellow ultramarine dye (0.35) Amount of0.9 1.15 1.5 0.8 0.15 0.9 pigment/dye Himilan 1855 50 50 50 Himilan 155550 50 50 Thermoplastic 1 1 1 polyurethane Titanium 1.8 1.8 1.0 1.0 0 1.50 1.8 oxide Lubricant 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 IntermediateMaterial b b a layer L* value 98.5 98.5 65.0 Outermost Haze 98.47 98.4198.54 98.4 96.27 96.41 81.09 98.47 layer Total light 8.3 1.99 8.32 1.782.02 49.55 47.77 8.3 composition transmittance properties Diffuse 8.171.96 8.2 1.67 78.96 47.77 38.74 8.17 transmittance Color tone L* 78.1778.48 89.23 90.14 93.4 67.7 64.9 55.4 of ball a* 7.37 8.75 −9.89 −9.41−23.8 47.7 −12 3.3 b* −12.43 −13.29 25.03 25.4 90.9 7 −36.8 −22.9Saturation 14.5 15.9 26.9 27.1 7.7 12.2 11.3 23.6 L* value difference−20.3 −20.0 −9.3 −8.4 −5.1 −30.8 −33.6 −9.6 between outermost layer andintermediate layer Ball Weatherability Exc. Exc. Exc. Exc. Fair GoodExc. Fair appearance Elegant feel Exc. Good Exc. Good Exc. Fair FairFair Pastel feel Exc. Exc. Exc. Exc. NG NG Fair NG Transparent Exc. Exc.Exc. Exc. Good Good Fair Exc. feel

The materials mentioned in the table are described below.

-   -   Titanium yellow: Pigment Yellow 53 (CAS No. 8007-18-19)    -   Quinacridone Red: Pigment Red 202 (CAS No. 3089-17-6)    -   Ultramarine: Pigment Blue 29 (CAS No. 57455-37-5)    -   Cyclic dye: 2-Octadecyl-1-thioxane (CAS No. 27870-92-4)    -   Anthraquinone dye: Pigment Red 263    -   Himilan 1855: Zinc-neutralized ethylene-methacrylic acid-acrylic        acid ester copolymer available from DuPont-Mitsui Polychemicals        Co., Ltd.    -   Himilan 1555: Sodium-neutralized ethylene-methacrylic acid        copolymer available from DuPont-Mitsui Polychemicals Co., Ltd.    -   Thermoplastic polyurethane:        -   Available from DIC Bayer Polymer under the trade name PANDEX            T-R3080    -   Titanium oxide: Available from Ishihara Sangyo Kaisha    -   Lubricant: Magnesium stearate available from NOF Corporation

From the results in Tables 1 and 2, the respective comparative exampleswere inferior in the following ways to the examples of the invention.

In Comparative Example 1, compared with Examples 1 and 2 of theinvention, the pigment or dye was yellow, but titanium oxide was notincluded; the total light transmittance and the diffuse transmittancewere high. In addition, the a* and b* values for the ball were high. Forthis reason, the ball left an impression of elegance and transparency,but lacked a pastel feel

In Comparative Example 2, compared with Examples 3 and 4 of theinvention, the pigment or dye was red and titanium oxide was included.The ball lacked a pastel feel.

In Comparative Example 3, compared with Examples 3 and 4 of theinvention, the pigment or dye was blue, but titanium oxide was notincluded. As a result, the total light transmittance and diffusiontransmittance were high. The ball left a slight impression oftransparency, but lacked an elegant feel.

In Comparative Example 4, compared with Example 1 of the invention, theintermediate layer was changed to one having a small L* value. As aresult, although the ball left an impression of transparency, the colorof the intermediate layer showed through, resulting both in a lack of apastel feel and a lack of an elegant feel.

Japanese Patent Application No. 2010-176316 is incorporated herein byreference.

Although some preferred embodiments have been described, manymodifications and variations may be made thereto in light of the aboveteachings. It is therefore to be understood that the invention may bepracticed otherwise than as specifically described without departingfrom the scope of the appended claims.

1. A colored golf ball comprising a core, a cover of at least one layerencasing the core, and a coat of paint applied to a surface of anoutermost layer of the cover, wherein the outermost cover layer isformed of a resin composition comprising: (a) a thermoplastic resin, (b)a color pigment or dye, (c) titanium oxide, and (d) a lubricant, theresin composition having a total light transmittance of at least 1.0 butnot more than 40 and a diffuse transmittance of at least 1.0 but notmore than 40, and wherein the paint coat contains a polarizing pigment.2. The colored golf ball of claim 1, wherein the color pigment or dye(b) is selected from the group consisting of red pigments, bluepigments, yellow pigments, green pigments, violet pigments and blackpigments.
 3. The colored golf ball of claim 1, wherein the resincomposition is formulated as follows: (a) from 90 to 99 wt % of athermoplastic resin, (b) from 0.003 to 2 wt % of a color pigment or dye,(c) from 0.01 to 2.5 wt % of titanium oxide, and (d) from 0.1 to 5.5 wt% of a lubricant.
 4. The colored golf ball of claim 1, wherein the ballhas a surface with a color tone which, expressed numerically in theL*a*b* color space according to JIS Z8729, is: L*=50 to 95, a*=−20 to30, and b*=−45 to
 45. 5. The colored golf ball of claim 1, wherein thepaint coat comprises 100 parts by weight of a base resin, from 0.05 to 1part by weight of a fluorescent whitener and from 0.1 to 3 parts byweight of a polarizing pigment, and the fluorescent whitener andpolarizing pigment have a weight ratio therebetween of from 0.05 to 5.0.